Journal
FRONTIERS IN PLANT SCIENCE
Volume 14, Issue -, Pages -Publisher
FRONTIERS MEDIA SA
DOI: 10.3389/fpls.2023.1204279
Keywords
DNA methylation; CHH methylation; transposable elements; CMT2; RdDM; embryogenesis
Categories
Ask authors/readers for more resources
Through profiling DNA methylation at five stages of Arabidopsis embryogenesis, we found that the gradual increase in mCHH coincides with the expansion of small RNA expression and the spreading of mCHH to nearby sites. We also identified distinct methylation dynamics in different groups of mCHH targets, which are associated with the length, location, and cytosine frequency of transposons.
CHH methylation (mCHH) increases gradually during embryogenesis across dicotyledonous plants, indicating conserved mechanisms of targeting and conferral. Although it is suggested that methylation increase during embryogenesis enhances transposable element silencing, the detailed epigenetic pathways underlying this process remain unclear. In Arabidopsis, mCHH is regulated by both small RNA-dependent DNA methylation (RdDM) and RNA-independent Chromomethylase 2 (CMT2) pathways. Here, we conducted DNA methylome profiling at five stages of Arabidopsis embryogenesis, and classified mCHH regions into groups based on their dependency on different methylation pathways. Our analysis revealed that the gradual increase in mCHH in embryos coincided with the expansion of small RNA expression and regional mCHH spreading to nearby sites at numerous loci. We identified distinct methylation dynamics in different groups of mCHH targets, which vary according to transposon length, location, and cytosine frequency. Finally, we highlight the characteristics of transposable element loci that are targeted by different mCHH machinery, showing that short, heterochromatic TEs with lower mCHG levels are enriched in loci that switch from CMT2 regulation in leaves, to RdDM regulation during embryogenesis. Our findings highlight the interplay between the length, location, and cytosine frequency of transposons and the mCHH machinery in modulating mCHH dynamics during embryogenesis.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available